title: Sleep disturbance and affective comorbidity among episodic migraineurs.
abstract: BACKGROUND
  Disturbances in sleep are common among migraineurs, particularly those with frequent (ie, chronic) migraine. Examination of specific types of sleep disturbance and behaviors among episodic migraineurs, however, has not been sufficiently explored. Further, few studies have investigated whether sleep disturbance is attributable to comorbid affective symptomatology.
  
  
  OBJECTIVE
  The present case-control study sought to (1) assess sleep quality, daytime sleepiness, and sleep hygiene among a large sample of episodic migraineurs; (2) quantify relations between sleep disturbance and headache-related variables; and (3) determine if these relations remain after accounting for comorbid depression and anxiety.
  
  
  METHODS
  Two hundred ninety-two undergraduate students (69.9% female, mean age = 19.19, standard deviation [SD] = 3.21 years) completed measures of sleep quality, daytime sleepiness, and sleep hygiene along with well-validated measures of depression and anxiety symptomatology. Those screening positive for migraine were subsequently administered a structured diagnostic interview to verify diagnosis of migraine consistent with the International Classification of Headache Disorders, 2nd edition. Episodic migraineurs and non-migraine controls were compared on the sleep disturbance variables, and among those with migraine, relations with headache frequency, severity, and disability were quantified with linear regression analyses.
  
  
  RESULTS
  Seventy-eight (26.7%) participants met International Classification of Headache Disorders, 2nd edition criteria for episodic migraine. Compared with participants without migraine, episodic migraineurs reported poorer sleep quality (mean = 8.90 [SD = 3.39] vs 6.63 [SD = 3.02], P < .0001), with 85.9% reporting clinically significant poor sleep quality (vs 62.0% of controls). Poor sleep quality was significantly associated with headache frequency and headache-related disability, accounting for proportions of variance (14.8% in frequency and 18.2% in disability, both P ≤ .001) similar to those attributable to depression and anxiety. These relationships remained significant after controlling for these affective symptoms, in which sleep quality accounted for 5.3% and 5.8% of unique variance in frequency and disability, respectively (P < .05). By comparison, daytime sleepiness and poor sleep hygiene were not consistently associated with migraine or migraine-related variables.
  
  
  CONCLUSIONS
  Consistent with prior studies on chronic migraine, poor sleep quality is uniquely associated with episodic migraine, and this relationship is not solely attributable to comorbid psychiatric symptomatology. Sleep quality should be preferentially assessed (vs sleepiness and sleep hygiene) when subjective self-report measures of insomnia are used in clinical headache settings. Future studies should supplement these findings by evaluating the efficacy of interventions that specifically target sleep quality and insomnia (eg, stimulus control, sleep restriction) among episodic migraineurs.
authors.affiliation: Department of Psychology, University of Mississippi, Oxford, MS, USA.
authors.forename: A Brooke
authors.initials: AB
authors.lastname: Walters
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Hamer
authors.forename: Todd A
authors.initials: TA
authors.lastname: Smitherman
mesh_terms: D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D011795:Surveys and Questionnaires / Q000592:standards; D013997:Time Factors; D055815:Young Adult
keywords: insomnia; migraine; psychiatric comorbidity; sleep hygiene; sleep quality